MDA-MDH Community Public Water System Well Pesticide Reconnaissance Study David Rindal Compliance Engineer November 15, 2017
Background
Background Joint project Minnesota Department of Agriculture (MDA) Minnesota Department of Health (MDH) Community Public Water System (CPWS) reconnaissance 108 wells sampled Similar project conducted in 2010 Funding sources MDA: pesticide fees, Clean Water Land and Legacy funds MDH: service connection fees, EPA PWS Supervision program
Background 2015 Well Locations
MDA-MDH Study vs. MDA Monitoring Background
Sample Collection February / March 2015 MDH District Engineers Raw ground water taps
Sample Analysis MDA Laboratory Services performed pesticide analyses GC-MS/MS LC-MS/MS 135 different pesticide and degradates Measured at nanograms per liter (ng/l) MDH Public Health Laboratory performed water quality analyses
Neonicotinoids Acetamiprid Clothianidin 8
Neonicotinoids Dinotefuran Imidacloprid 9
Neonicotinoids Thiacloprid Thiamethoxam 10
Neonicotinoids Nithiazine 11
Results
Results 19 (of 135) different pesticide compounds detected 72 samples out of 108 locations had at least one pesticide detected (67% of wells) Metolachlor ESA most frequently detected (63% of the wells) No pesticides measured above applicable drinking water guidance values or standards
Results Number of Detections 80 70 60 50 40 30 20 10 0 Herbicide Herbicide Degradate Fungicide n = 108 Detected Analyte
Results Total pesticide compounds detected 75% of wells had three or fewer pesticide compounds detected 1 well had 9 pesticide and degradate compounds 1 well had 10 pesticide and degradate compounds
MDA Common Detection Pesticides MDA Common Detection Pesticide Acetochlor Alachlor Atrazine Metolachlor Metribuzin Common Product Names Harness, Confidence Lasso, Intrro Aatrex, Brawl II Dual, Magnum Sencor, Axiom Rarely exceed health standards
Results - Acetochlor No parent compound detected
Results - Alachlor No parent compound detected
Results - Atrazine Parent compound found most frequently in this Study (7 times) 4 out of 7 detections were found in southeast MN
Results - Metolachlor Parent compound detected once Degradates detected most often Metolachlor degradates were detected mainly in the southern two thirds of MN
Results - Metribuzin Only 1 of 4 metribuzin degradates detected Metribuzin DADK was detected in the central part of MN
Results Pesticide compounds detected in greater than 10% of samples 2015 Detection and Frequency (n=108) 2015 Median (ng/l) 2015 Maximum (ng/l) Health Reference Value (ng/l) Health Reference Value Type Acetochlor ESA 21 (19%) ND 1,460 300,000 HRL 11 Alachlor ESA 49 (45%) ND 3,130 60,000 RAA 15 Alachlor OXA 12 (11%) ND 111 60,000 RAA 15 Metolachlor ESA 68 (63%) 27.3 3,690 800,000 HRL 11 Metolachlor OXA 36 (33%) ND 996 800,000 HRL 11
Results Bromide and Chloride
Chloride : Bromide Comparison Pesticides Detected with Chloride and Bromide Results No Pesticides Detected with Chloride and Bromide Results Total Samples 72 35 Pesticide Detections (n = 108) Results Bromide and Chloride 236 0 Maximum [Cl - ]/[Br - ] 11,760 2,445 90 th Percentile [Cl - ]/[Br - ] 1,270 449 Mean [Cl - ]/[Br - ] 811 241 Median [Cl - ]/[Br - ] 490 122
Results Nitrate plus Nitrite
Results Nitrate plus Nitrite
Results Nitrate plus Nitrite Nitrate + Nitrite Comparison Pesticides No Pesticides Detected Detected Total Samples 72 36 Pesticide Detections (n=108) 236 0 Maximum Nitrate + Nitrite, mg/l 18.10 2.08 90 th Percentile Nitrate + Nitrite, mg-n/l 5.88 0.44 Mean Nitrate + Nitrite, mg-n/l 2.38 0.47 Median Nitrate + Nitrite, mg-n/l 0.99 0.40
Summary
2010 and 2015 Common Well Locations Summary
Summary Pesticide Analyte 2010 and 2015 Comparisons 2010 Detection Frequency (n=80) 2015 Detection Frequency (n=80) 2010 Median (ng/l) 2015 Median (ng/l) Acetochlor ESA 19% 21% ND ND Alachlor ESA 56% 49% 53.5 ND Alachlor OXA 10% 13% ND ND Bentazon 15% 8% ND ND Metolachlor ESA 70% 70% 65 65.1 Metolachlor OXA 38% 38% ND ND
Summary Nitrate and Pesticide Co-Occurrence 2010 and 2015
Summary 80 locations from 2010 were sampled in 2015 Alachlor and bentazon showed greater than five percent decreases in detection frequency between 2010 and 2015 All detections were well below the MDH or EPA established standards or established health reference values Metolachlor ESA was the most frequently detected compound and was found in 63 percent of the sample wells
19 of 135 pesticide compounds detected 72 of 108 samples positive 0 Neonicotinoids
Acknowledgements
Heather Johnson, MDA Brennon Schaefer, MDA Dylan Timm, MDA Todd Johnson, MDH Anna Schliep, MDH MDA Laboratory Services MDH Public Health Laboratory MDH district engineers Community public water systems Acknowledgements
Thank you! David Rindal david.rindal@state.mn.us 651-201-4660 Drinking Water Protection health.state.mn.us/water/
Supplemental Material
Supplemental Material Pesticide Monitoring Regions (PMRs) Monitoring and data analysis completed for 10 Pesticide Monitoring Regions (PMRs)
Supplemental Material Median Metolachlor Concentration (ng/l) 800 700 600 500 400 300 200 100 0 2015 Median Combined Metolachlor and Degradate Concentrations, MDA Groundwater Monitoring Wells and Community Public Water Supply Wells 1411 0 2 0 1 102 25 16 5 163 148 PMR 1 PMR 2 PMR 3 PMR 4 PMR 5 PMR 6 PMR 7 PMR 8 PMR 9 PMR 10 Numbers above the bars are number of samples collected Pesticide Monitoring Regions 28 19 37 17 20 18 MDA Wells
Supplemental Material Common Name 2010 Detection Frequency (n=80) 2015 Detection Frequency (n=80) 2010 Median (ng/l) 2015 Median (ng/l) 2010 90 th percentile (ng/l) 2015 90 th percentile (ng/l) 2010 Maximum (ng/l) 2015 Maximum (ng/l) Reference Value (ng/l) Value Type 2,4-D 1% 0% nd nd nd nd 14.4 nd 2,000 RA 14 Acetochlor ESA 19% 21% nd nd 85 96 2,180 1,460 300,000 HRL 11 Acetochlor OXA 5% 6% nd nd nd nd 71 81 100,000 HRL 11 Alachlor ESA 56% 49% 54 nd 1,270 1,405 4,600 2,140 50,000 RAA 16 Alachlor OXA 10% 12% nd nd 32.4 35.5 187 111 50,000 RAA 16 Atrazine 5% 4% nd nd nd nd 90 81 3,000 HRL MCL DACT Atrazine* 6% na nd nd nd na 104 na 3,000 HRL DEDI Atrazine* na 5% na nd na nd na 83 3,000** Parent HRL MCL Desethylatrazine 5% 4% nd nd nd nd 90 81.7 3,000** Parent HRL MCL Hydroxyatrazine 4% 1% nd nd nd nd 8 10.5 20,000 HBV 05 Bentazon 15% 7% nd nd 2 nd 116 56.2 30,000 HBV 15 Bromacil 0% 2% Clopyralid 0% 1% Dimethenamid ESA 2% 1% Dimethenamid OXA 1% 0% Imazapyr 0% 1% Metalaxyl 0% 1% Metolachlor 1% 1% nd nd nd nd nd 76.2 30,000 HBV 14 nd nd nd nd nd 928 200,000 RA 14 nd nd nd nd 19 13.3 300,000 RAA 13 nd nd nd nd 15 nd 300,000 RAA 13 nd nd nd nd nd 18.3 900,000 RA 14 nd nd nd nd nd 9.57 20,000 RA 14 nd nd nd nd 80 56 300,000 HRL 11 Metolachlor ESA 70% 70% 65 64 694 582 6,170 3,690 800,000 HRL 11 Metolachlor OXA 38% 37% Metribuzin DADK 0% 1% Picloram 1% 0% nd nd 89 155 2,120 996 800,000 HRL 11 nd nd nd nd nd 607 10,000 RAA 12 nd nd nd nd 155 nd 300,000 RA 14
Supplemental Material Common Name 2015 Detection and Frequency (n=108) 2015 Median (ng/l) 2015 75 th percentile (ng/l) 2015 90 th percentile (ng/l) 2015 Maximum (ng/l) Reference Value (ng/l) Value Type Acetochlor ESA 21 (19%) nd 86 90 1,460 300,000 HRL 11 Alachlor ESA 49 (45%) nd 178 1,365 3,130 60,000 RAA 15 Alachlor OXA 12 (11%) nd nd 35.2 111 60,000 RAA 15 Atrazine 7 (6%) nd nd nd 92.9 3,000 HRL MCL DEDI Atrazine 6 (6%) nd nd nd 182 3,000* Parent HRL MCL Desethylatrazine 7 (6%) nd nd nd 88.2 3,000* Parent HRL MCL Hydroxyatrazine 3 (3%) nd nd nd 44.7 20,000 HBV 05 Bentazon 9 (8%) nd nd nd 56.2 30,000 HBV 14 Bromacil 2 (2%) nd nd nd 76.2 30,000 HBV 14 Clopyralid 1 (1%) nd nd nd 928 200,000 RA 14 Dimethenamid ESA 2 (2%) nd nd nd 34.3 300,000* RAA 13 Imazapyr 3 (3%) nd nd nd 57 900,000 RA 14 Metalaxyl 1 (1%) nd nd nd 9.57 20,000 RA 14 Metolachlor 1 (1%) nd nd nd 56 300,000 HRL 11 Metolachlor ESA 68 (63%) 27.3 183 574 3,690 800,000 HRL 11 Metolachlor OXA 36 (33%) nd 26.7 134 996 800,000 HRL 11 Metribuzin DADK 1 (1%) nd nd nd 607 10,000 RAA 12
Graphic Background Notice the image in the background.